A standard ring-spinning or -twisting machine has a spindle bank on which a multiplicity of upright spindles are rotatable. These spindles normally carry sleeves on which respective rovings are wound up to form the desired yarn packages. The yarns or rovings run over ring guides or the like to the respective spindles.
Once a package is complete, the respective guide drops down to a level below the sleeve and winds several turns of the roving around a lower reserve region on the respective spindle. When the sleeve is subsequently doffed, the roving breaks, leaving the leading end of the incoming roving wound around the lower end of the spindle. Then a new spindle is set in place and the winding operation starts again with the thread caught on the lower reserve space being caught on the new sleeve and wound up, repeating the cycle.
Clearly a problem with this system is that the reserve surface quickly gets fouled with the roving, since several turns are added each time the sleeve is changed. These reserve surfaces must be cleared periodically.
Accordingly a machine has been proposed in European patent application 251,397 filed based on an Italian priority of 29 June 1988 by S. Sartoni et al that has a carriage that moves past the spindles and that carries equipment for clearing the reserve surfaces. This equipment includes a motorized scraper and a vacuum arrangement. In general such a system is quite complex and adds considerably to the cost of the apparatus.
Other similar devices are described in Swiss patent 432,319 assigned to Deutscher Spinnereimaschinenbau Ingolstadt, European patent application 219,129 assigned to Murao Boki KK, and German 1,760,775 and French 2,432,566 both of Zinser Textilmaschinen GmbH.